Expansion-bolt.



N o. 737,555. PATBNTED AUG. 25, 1903.-

mmm. w EXPANSION BOLT.'

, APPLIOAT'ION FILED Nov,.19. 1902. No Mmm..

TN: yann: Pcrsns co; PMow-UTHD.. WASHINGTDN, D. c.

UNiTnD STATES Patented August 25, 1903'.`

PATENT OFFTCE.

CHRISTIAN DORN, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR OF ONE- HALF TONVILLIAM Gr.V T. MAROELLUS, OF PHILADELPHIA, PENNSYLVANIA.

EXPANSION-BOLT.

SPECIFICATION forming part of Letters Patent No. 737,555., dated August25, 1903.

l Application filed November 19, 1902. Serial No. 132,023. (No model.)

To all wwm/ t may concern:

Be it known that I, CHRISTIAN DoRN, a citizen of the United States,residing in Philadelphia, Pennsylvania, haveinvented certainImprovements in Expansion-Bolts, of which the following is aspecification.

An expansion-bolt as that term is used in this specification means abolt whereby any desired object can be secured to a wall or othersurface by means of gripping devices contained in a recess formed in thewall and expanded against the sides of said recess by means of a wedge.Quite a number of devices of this character all having the sameprinciple of operation have been devised and: patented and are now inuse; and the object of my invention has been to simplify and cheapen theconstruction of such an expansion-bolt and to reduce the number of partsnecessary toits proper operation.

In the accompanying drawings, Figure lis a vertical section of anexpansion-bolt con structed in accordance with my invention. Fig. 2 isan external view of the parts of the same detached from each other. Fig.3 is a transverse section on the line c a, Fig. 1. Fig. 4 is atransverse section on the line b b, Fig. l; and Fig. 5 is alongitudinalsection of a special form of wedge-nut which I sometimes employ.

l represents part of a wall or other surface to which any desired objectis to be attached by means of an expansion-bolt or a number ofsuchbolts,this objectin the present instance being aconvexed plate orwasher 2. In the Wallis formed a recess 3 of the proper diameter anddepth for the reception ofthe member of the expansionbolt,these memberscomprising inthe present instance the wedge-nut 4, the counter-Wedge 5,and the screw-bolt 6. In the present instance the opening 3 is ofcircular form, and the wedge-nut4 and counter- Wedge 5 are externallyrounded to correspond with the shape of the opening; but in the event ofthe opening being of other crosssectional form the external shape of theWedges can be correspondingly changed. The inclined faces of thewedge-nut 4 and'connter-Wedge 5 bear upon each other, and the said nut 4and Wedge 5 bear externally upon opposite Walls of the opening. Thus,asshown in the drawings, the nut4 bears upon the bottom of the opening andthe wedge 5 upon the top of the same. Both nut and wedge are ribbedexternally, so as to bite into the Walls of the opening. The nut 4 has athreaded opening for the reception of the threaded portion of the bolt 6and is preferably counterbored, as shown at 7, beyond said threadedopening, so as to be free from contact with said threaded portion of thebolt. The counter-wedge 5 has a projecting sleeve 8, and both wedge andsleeve are centrally bored for the reception of the bolt 6, this borebeing slightly elongated, as shown in Fig. 4, in order to permit theWedge 5 to slide up and down upon the nut 4, as it is compelled to do inthe operation of the device. The outer end of the sleeve 8 bears againstthe inner face of the plate 2 or other object which is to be secured inposition, and the head of the bolt 6 bears upon the outer face of saidplate 2. When, therefore, the boltis turned in the proper direction, thewedge nut 4 will be drawn forward, and the eect of this action Will beto press the outer face of said Wedgenut firmly against one side of theopening 3 and the outer face of the counter-Wedge 5 firmly against theother side of said opening. Hence the bolt 6 and the object to beretained thereby will be rigidly held in place, there being a directoutward thrust upon both nut and wedge throughout the entire length ofeach of them, thus insuring their firm hold upon the Walls of theopening. The purpose of the outwardly extending sleeve S is to locatethe wedge-nut4andcounter-wedge 5 so far inwardly from the face of theWall that the latter will offer the proper .resistance to expansion andwill not be cracked or otherwise injured by the force exllled.

In applying the device the nut 4 and counter-wedge 5 are iirst placed inthe opening. The plate or other object 2 is then properly disposed uponthe face of the wall, and the bolt 6 is passed through the opening insaid plate and through the central bore of the wedge 5 and its sleeve 8and is screwed into the threaded opening of the nut 4 until the same hasbeen drawn up against the Wedge 5 and the desired expansion has beenefeoted. The

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opening in the plate 2 need only be large enough for the reception ofthe stem of the bolt. Hence the plate is not weakened, as it would be ifthe opening therein were large enough to permit the nut or Wedge to passthrough the same.

By using the nut 4 as one -of the gripping elelnents of the device Ireduce the number of parts employed and correspondingly cheapen andsimplify the construction of the device.

When the Wedge-nut has to be made of lead or other soft metal, as isrequired in some cases, Iprefer to cast the same around a nut 4J* ofiron or other hard metal, as shown in Fig. 5, so as to avoid thenecessity of cutting a thread in the softmetal and at the same timeobtain a stronger thread.

Having thus described my invention, I claim and desire to secure byLetters Patent- 1. The combination in an expansion-bolt, of a Wedge-nut,and aV counter-Wedge, each constituting a gripping member of the device,and a bolt passing through said expansionwedge and adapted to a threadedopening in the wedge-nut, substantially as specified.

2. The combination in an eizpansion-bolt, of a Wedge-nut constitutingone of the gripping members of the device and having a threaded openingand a counterbore adjacent thereto, a counter-wedge constituting theother gripping member of the device, and a bolt passing through saidcounter-Wedge and engaging with the threaded opening of the nut,substantially as specified.

3. The combination in an expansion-bolt, of a Wedge-nut and acounter-Wedge constituting the two gripping members of the device, saidcounter Wedge having an. out- Wardly-extending sleeve thereon, and abolt passing through said counter-Wedge and its sleeve and. engagingwith the threaded opening of the Wedge-nut, substantially as specified.

In testimony whereof I have signed my name to this specification in thepresence of two lsubscribing witnesses.

CHRISTIAN DORN.

